Biodiv Sci ›› 2022, Vol. 30 ›› Issue (5): 21031.  DOI: 10.17520/biods.2021031

• Original Papers: Genetic Diversity •     Next Articles

Assessment of SNPs-based genomic diversity in different populations of Eastern Asian landrace horses

Togtokh Mongke, Dongyi Bai, Tugeqin Bao, Ruoyang Zhao, Tana An, Aertengqimike Tiemuqier, Baoyindeligeer Mongkejargal, Has Soyoltiin, Manglai Dugarjaviin(), Haige Han()   

  1. Inner Mongolia Key Laboratory of Equus Genetics, Breeding and Reproduction, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018
  • Received:2021-07-20 Accepted:2022-04-29 Online:2022-05-20 Published:2022-05-20
  • Contact: Manglai Dugarjaviin,Haige Han


Aims: The genetic diversity within landrace horse breeds changes over time and is greatly affected by breeding strategies. In the past 300 years, standardized horse breeds have been bred for prominent traits, and these breeds have been then largely introduced to improve the landrace populations which has been resulted in the reduced genetic diversity or genetic differentiation within landrace population. The aim of this study was to assess the genetic diversity of Eastern Asian landrace horse populations which will constitute the basis for the conservation of landrace horse genomic resources as well as breeding of new strain of horses.

Methods: Here we sequenced the whole genome of 70 horses from five Eastern Asian horse breeds (Hequ horse and Tibetan horse, Southwest horse, Mongolian horse, and Kazakh horse), two Western Asian breeds (Arabian horse, Akhal-Teke horse), and two European breeds (Shetland pony and Clydesdale horse). This newly generated data was combined with 100 previously published Inner Mongolian horse SNPs data to investigate the genomic diversity of the Asian landrace horse breeds.

Results: Our results suggest that the Eastern Asian landrace horse breeds have significant genetic differentiation and higher genetic diversity compared with non-Eastern Asian horse breeds. In particular, the Inner Mongolian horse populations showed the highest genetic diversity, and genetic differentiation has been observed among the populations sampled in Inner Mongolia Autonomous Region, China, which may reflect the exotic genetic influence on the genetic improving some of the local populations, such as Baicha iron hoof horse and Abag horse populations. There was no observation of this gene flow in the Hequ horse and Tibetan horse.

Conclusion: The genetic diversity of landrace horses changes and even decreases through hybridization between native and introduced modern standardized horse breeds. The wild ancestral population of domestic horses is now wholly extinct; therefore, it is imperative to maintain and protect the genetic diversity of landrace horses. The expansion of the modern standardized horse bloodlines has contributed to genetic diversity decreases and genetic differentiation increases in landrace horses. The Eastern Asian landrace horse breeds have higher genetic diversity, and endangered Baicha iron hoof horse and Abag horse have occurred significant genetic differentiation trend from the Mongolian horse population. Genetic swamping is the major concern for small population horses, therefore, the genetic conservation of Baicha iron hoof horse warrants particular attention.

Key words: Eastern Asian horse breeds, genetic diversity, genetic differentiation, introduction and breeding, genetic resources conservation